Lead-sharpening device



April 6 1926. 1,579,972

E. THORESEN LEAD SHARPENING DEVICE Filed August 5, 1925 INVENTOR f` wrrNEssf W AvroRNEv lili Patented Apr. 6, i926.

UNITED -STA'gIES ninna rnonnsniv, or CLEVELAND, oiiio.

- LEAD-SHARPENING- DEVICE.

Application ledAugfust 3, 1925. Serial No. 47,912.

To all whom/t may concern: y

Be it known that I, EINAR TrionnsnN, a 'subject of the Kingdom ofy Norway, residing at Clevcland,iii the count-y of Cuyahofg'a and State of Ohio, have invented newV {aind useful Improvements in Lead-Sharpen ling Devices, of which the following is a specification. y

This invention relates to lead sharpening `devices desipnied for pointing the leadsmof peneis, an object `being to provide a device `of this character which is especially adapted for pointing compass leads.

Another object of tlie invention is the provision of a lead sharpening device by means of which compasses or pencil leads may. he sharpened either yupon one side of the point, or the other, or upon both sides.

With the above and other objects in view, the invention further includes the following novel features and details of construction, to be hereinaftermore fully described illustrated in the accompanying drawings and pointed out in the appended claims.

In the drawings v Figure 1 is a sectional view illustrating` the use of the invention.

Figure 2 is a top plan view of the device.

Figure 3 is a fragmentary elevation showing a portion of one of the inclined abrasive surfaces.

Figure i is an elevation partly broken away showing a slightlydifferent form of the invention,

Referring to the drawings in detail wherein like characters of reference denote corresponding parts, the reference character 10 indicates a cup-like receptacle which is preferably formed of thin sheet metal and which is designed to hold a plurality of annular concentricaly arranged sharpening elements 11, the latter extending around a centering member 12.

The sharpening elements may be formed of any suitable material, such as hardened steel, carborundum and so forth, while the centering element is preferably formed ofl soft metal and is provided with a centralindentation to receive the needle point of one leg 13 of a compass, the other leg 14 carrying alead 15. The lead 15 is usually sharpened by flattening one or both sides and to facilitate this, the elements 11 are provided with beveled or inclined abrasive surfaces 16, these surfaces being knurled or serrated when the Sharpening elements are. of bard? Y cned steel. To provide for sharpening the lead upon both sides, the outer and inter-v mediate sharpening elements have their abrasive surfaces relatively inclined so as to provide a substantially V-sliaped groove v17 whose opposed walls forni the sharpening surfaces so that by arrangingthe compass in the position shown in Figure 1 and moving said compass in a rotary direction, the lead 15 will be sharpened as indicated. The innermost sharpening element 11 and the intermediate sharpening element have .their opposed abrasive surfaces spaced by means of a spacing ring 18, so that by contact with the surface a, the outer side of the lead will be beveled while engagement of the lead with the surface L wiil bevel the inside of the lead. The sides of the receptacle 1()v are preferably extended above the upper faces of the sharpening elements as indicated at 19.

In Figure d, a single annulai` sharpening element 20 is provided within a casing 10', the element being secured in place by indenting a portion of the casing so as to engage the walls of the socket 21 provided iny the sharpening element 20, any desired number of these indented portions and sockets being provided. A press fit is thus made to hold the sharpening element in place.

Positioned concentrically within the annular sharpening element 2O is a combined centering element and guide member 22 whose outer tapered edge 23 is rounded and spaced from the abrasive surface 24 of the sharpening element 20, so that the lead may rest upon this tapered rounded edge 23 and engage with the abrasive surface to bevel one side of the lead. The member' 22 is held in place by a 10 as indicated at 25. A centering notch 26 receives the needle point of the compass.

If desired, this form of the invention as well as that illustrated in Figures 1 and 2 may be provided with a cover 27 and a felt or other coinpressible ring 28 may be interposed between this cover and the members 2O and 22. The space provided between the sharpening element 20 and the 'under inclined face of the member 22 may receive the dust from the lead.

The invention is susceptible of various changes in its form, proportions and minor details of construction and the right is herein reserved to make suoli changes asproperly fall within the scope of the appended .claims press lit with the casing 1j LA lead sharpening device Jfor Compasses Comprising a sharpening element havingan inclined abrasive surfacemeans'toguide the lead along said surface and lmeans to sup'- portI one leg of the Compass.u

2. A lead sharpening .device for Compasses Comprising a sharpening element having a circular abrasive surface and means .located Having described the invention what is concentric of the V'abrasive surface to provide a supporting Center for one leg ofthe compass. 4

.13. A lead sharpening device for Compasses Comprising Va supporting Center `for one leg of a Compass and concentrically' arranged 'oppositely inc`ined abrasive surfaces-encircli n said supporting center.

`4. lead sharpening device for Compasses comprising. a supportingvcenter for one leg vthe vsupporting Center, oppositely inclined abrasive surfaces for said elements and meansitohold the elements in position.

"5ft/.Al lead sharpening device for Compasses comprisinga supporting Center -for one leg of' a Compass, a plurality of annular sharpening elements arranged concentrically of the supporting'center, oppositely inclined abrasive surfaces for said elements Aand a substantially cup shaped receptacle receiving'y said eements ,andproviding an annular flange extending above ,the upperface of saidy elements. f

lntestimony whereof I affix my signature.

@man -rHoREsEN 

